Starter and Alternator question

Tony.dreamer

Tony.dreamer

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On my 1971 2800 CS build, should I consider :
1-ALTERNATOR ...buying a new Alternator or use the existing one from the car? Are there any benefits of having a new type alternator with internal voltage regulator? What are the pros and cons. As you know the connector of the Alternator is rather unique , or is it?
2- STARTER... I had a shop check the one I pulled from the car and was told it is fine.
Can this started be used with m30B34 or 35?
I see no reason why it should be but I thought I ask anyways.

The underplaying questions stems from the fact that I am having a German company build me a new wiring harness using the connectors that are unique to E9. I figure I need to completely understand how the wiring works before I spent the money and minimize the surprises later ...

Thank you for your input!
 
Early e9s had an external voltage regulator (the larger of the metal cans on the LH fender ) Modern alts have the reg built in. Either work well although the modern one are likely to be more reliable in the long term. The purist would insist on the external reg though.
Starters are ASFIK are interchangeable throughout the M30 powered cars.
 
Do the internal e12 style. You can leave that external regulator in place for purity if you'd like.

My old alt had a very fried wire going to the regulator. I wouldn't chance it again.
 
Also, isn't there a smaller starter you can put on an m30?

If so, do it and buy it brand new. A starter is something you don't want to replace later. Major PITA.
 
teahead said:
Do the internal e12 style. You can leave that external regulator in place for purity if you'd like.
My old alt had a very fried wire going to the regulator. I wouldn't chance it again.
Click to expand...

I agree with teahead - modern, internally-regulated alternators are more reliable. Also the electronic regulation in the these units is more accurate than the mechanical regulation used originally on the e9 and e3's, though admittedly, the old-style regulators work well enough for the 1970's era electronics in these cars.

Note that when teahead says "You can leave that external regulator in place for purity" he means that you can leave it mounted, but unconnected. It's just there for show, so be sure to polish up the housing.
 
teahead said:
Do the internal e12 style. You can leave that external regulator in place for purity if you'd like.

My old alt had a very fried wire going to the regulator. I wouldn't chance it again.
Click to expand...
So I have the wires made as original and connect them to Regulator as normal if I used a newer styler Alternator?
What about the connector is the picture . Is the E12 style alternator have the same connector as pictured above?
 
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You harness has a separate three wire group (red, black, blue) with that plug on each end included in a plastic sleeve. You just remove it. However, you take the blue wire from the the firewall to the now disconnected regulator and run it to the d+ terminal on the new single wire Alt. Pretty simple.
 
The E12 alt requires a diff kind of plug (single wire). Like Chris says, it's only a blue wire that goes there for the new e12 version, so I just ran a spade terminal on it, but if your'e getting a new harness built, might as well use the correct E12 plug to put it in there so it looks more OEM.
 
HB Chris said:
You just remove it. However, you take the blue wire from the the firewall to the now disconnected regulator and run it to the d+ terminal on the new single wire Alt. Pretty simple.
Click to expand...
Wow Guys , you amaze me! That is a very precise instruction. If I understood you correctly I pull out the black three connector sleeve on both ends, as a harness by itself...!!?? I have to go back and look to see if mine has the same connectors on each end. I guess it is wrapped with tape so I missed what Chris noted ...
So , no wire should touch the regulator if I leave it there for cosmetics, as it just sits there on the fire wall.... ??
 
teahead said:
Also, isn't there a smaller starter you can put on an m30?

If so, do it and buy it brand new. A starter is something you don't want to replace later. Major PITA.
Click to expand...
i have a complete and running 1981 E12 that I can use . So far I am reluctant to tear it apart as I think I might rebuild the engine and use it toghther with the 5 speed on another build.
 
Tony.dreamer said:
Wow Guys , you amaze me! That is a very precise instruction. If I understood you correctly I pull out the black three connector sleeve on both ends, as a harness by itself...!!?? I have to go back and look to see if mine has the same connectors on each end. I guess it is wrapped with tape so I missed what Chris noted ...
So , no wire should touch the regulator if I leave it there for cosmetics, as it just sits there on the fire wall.... ??
Click to expand...

Correct, you got it. Or you can leave the blue wire at the regulator with a spade and then run it to the Alt, either way works. I will bet your new harness won't have the three wires, it is separate but sits in a tube with the positive battery cable to the Alt. Use a ring terminal for the blue wire on the Alt.
 
HB Chris said:
I will bet your new harness won't have the three wires, it is separate but sits in a tube with the positive battery cable to the Alt. Use a ring terminal for the blue wire on the Alt.
Click to expand...

I am making a completely new wiring harness using the old connectors. I can ask for alterations (modifications ) now.
So far I my list include
1- three wire flasher Relay connector ( as compared to 4 )
2- new head light connectors
3- E12 Style Alternator harness

What else?
 
Not sure....provisions for relays for the power windows if you don't have a '74+?

Fuel injection setup?

Again, the blue wire is just for the idiot light on the instrument panel. Once you disconnect the 3-wire plug from the old alt, you'll see how it's wired up. IIRC, two wires goes to the now-unused ext regulator and the blue wire to the idiot light.
 
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HB Chris said:
It’s a single wire Alt, not e12 specific, that’s all.
Click to expand...
Thank you again ! I think I got it now. What guage wire do you recommend? Or the wire manufacture should know that? Or I can have them make the wires as original and do what you recommend , just in case some purist bought the car after my time time...

Also what do you recommend for B34 or B35 wiring harness connection to the Systems ? Any thoughts on that. I will be talking directly to SfDon also.
 
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